Secure File Split/Join Tool - Enterprise Edition v5.5

FIXES IN v5.5:

- Fixed Ed25519 import compatibility
- Correct GF(256) implementation using log/antilog tables
- Share authentication key derived from master_key
- Shares bound to archive_id
- Fixed compression flush accounting
- Shard magic/version validation
- Single signing identity
- Password verifier for immediate feedback
- Nonce counter design for deterministic uniqueness
- CLI password prompt without command-line password exposure

REQUIREMENTS:

- Python 3
- pycryptodome
- argon2-cffi
- colorama
- tqdm
- zfec
- zstandard
- blake3
- filelock
- psutil

USAGE:

    fsplit --examples

Example:

    fsplit --split secret.pdf --parts 5 --threshold 3 --password

Recovery:

    fsplit --join secret --out recovered.pdf         --disk part_1 part_2 part_3         --password
